v3.25.4
Property, plant and equipment (Detail) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Insurance and Other [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross $ 62,979 $ 58,711
Property, plant and equipment, accumulated depreciation (31,094) (28,640)
Total property, plant and equipment, net 31,885 30,071
Insurance and Other [Member] | Land, buildings and improvements [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 22,034 20,735
Insurance and Other [Member] | Machinery and equipment [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 34,733 32,475
Insurance and Other [Member] | Furniture, fixtures and other [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 6,212 5,501
Railroad [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 94,699 91,672
Property, plant and equipment, accumulated depreciation (22,327) (20,411)
Total property, plant and equipment, net 72,372 71,261
Railroad [Member] | Land, track structure and other roadway [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 76,764 74,093
Railroad [Member] | Locomotives, freight cars and other equipment [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 15,772 15,766
Railroad [Member] | Construction in progress [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 2,163 1,813
Utilities and Energy [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 157,370 146,885
Property, plant and equipment, accumulated depreciation (45,002) (43,116)
Total property, plant and equipment, net 112,368 103,769
Utilities and Energy [Member] | Utility generation, transmission and distribution systems [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 109,815 103,015
Utilities and Energy [Member] | Interstate natural gas pipeline assets [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 21,334 20,237
Utilities and Energy [Member] | Independent power plants and other [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 15,630 14,840
Utilities and Energy [Member] | Construction in progress [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 10,591 8,793
Railroad, Utilities and Energy [Member]    
Property, Plant and Equipment [Line Items]    
Total property, plant and equipment, net $ 184,740 $ 175,030